Cardiac manifestations of igg4-related disease

Introduction

IgG4-related disease (IgG4-RD) is an immune-mediated fibro-inflammatory condition that affects multiple organ systems. Cardiovascular involvement has not been systematically studied, though case reports of putative involvement with severe consequences for affected patients have emerged. We aim to investigate and define the novel cardiovascular phenotype of IgG4-RD using cardiovascular magnetic resonance (CMR) imaging.

Methods

We recruited 11 patients (6 female, 61 ± 11 years, 9 with active disease (8 with pancreatic involvement, 3 parotid, 5 bile ducts, 5 kidneys and 3 cardiovascular)) with histologically confirmed IgG4-RD from a tertiary referral IgG4-RD clinic. These patients underwent a CMR scan performed at 1.5T including cine images, myocardial tagging, native T1 mapping, late gadolinium enhancement (LGE) and extracellular volume (ECV) imaging. Reference values were generated from 10 healthy controls with no cardiac disease (50% female, 35 ± 8 years). For T1-mapping, at least 15 healthy controls of each sex (15F and 17M) were used to establish sex-specific local normal ranges per guidelines. Results are presented as mean ± standard deviation unless otherwise stated.

Results

Patients with IgG4-RD had similar cardiac geometry to the reference group, with an average left atrial volume (LAV) of 80 ± 29ml, right atrial volume (RAV) 72 ± 46ml, left ventricular end-diastolic volume (LVEDV) 144 ± 32ml and right ventricular end-diastolic volume (RVEDV) 150 ± 45ml (Table 1). Average left and right ventricular ejection fractions (LVEF and RVEF) were 60 ± 4% and 59 ± 4%, respectively (Table 1). IgG4-RD patients showed significantly reduced global longitudinal strain (GLS) (-16.8 ± 2.3% vs -18.7 ± 1.6%, p=0.045) (Table 1). Male IgG4-RD patients (n=5) as a group showed a significantly higher average myocardial T1 value relative to the reference group, with 3/5 male patients having an abnormally high myocardial T1 (>2SD above limit of normal). Female IgG4-RD patients (n=6) had similar and normal myocardial T1 values to the reference group (Table 1). Seven of the 11 IgG4-RD patients showed LGE, with 6 of these in a non-ischaemic pattern (Table 1). ECV was not statistically different from reference values (29.5 ± 2.5% vs 27.9 ± 2.5% reference value, p=0.192) (Table 1).

Conclusion

Patients with IgG4-RD in this cohort demonstrated signs of cardiovascular involvement, including subclinical systolic dysfunction, elevated native T1 times and myocardial fibrosis. Future work in larger cohorts should seek to further define the novel cardiovascular phenotypes of this condition including the effects of systemic immunosuppressive therapy on cardiovascular involvement.

Conflict of Interest

None